The invention relates to internal combustion engines, in particular to rotary engines whose working members make oscillatory motions about an axle fixed on a rotor.
Known is a rotary internal combustion engine, comprising a rotor having radial-longitudinal posts and longitudinal blades swivel-mounted in the area of their external diameter, which blades have carriers that contact a guiding means, the rotor being positioned in a cylindrical body limited at its end faces by lateral walls and having an inlet opening and an outlet opening, a working chamber being defined by the external surface of a longitudinal blade, the cylindrical surface of the body and by the lateral walls of the body. A coaxial driven shaft is provided having additional radial posts and bell cranks articulated to the rotor working blades. (USSR Inventor""s Certificate N 1518555 IPC F 02 B 53/00, published 1989).
The air in the engine is compressed by rotation of adjacent blades of the rotor and rotation of the driven shaft about the posts when a cam is subjected to being rolled upon by a follower roller of the adjacent blades"" articulation.
A drawback of the known invention is the presence of an auxiliary driven shaft, which, furthermore, rotates at a variable velocity with respect to the driver shaft rotation angle, which makes the construction of this device complex. It should be noted that in this solution, as in many internal combustion engines, only the exterior side of the blades (one side of a cylinder in piston internal combustion engines) participates in the work cycle. From the point of view of the work cycle, the space under the blades is not utilized.
This drawback is eliminated in another technical solution, namely, in a rotary internal combustion engine that comprises a rotor having longitudinal flaps that are swivel mounted thereon in the area of the external diameter along its rotation axis and separate one from another the spaces arranged therein on both sides of each of the flaps, and which rotor is installed in a cylindrical body on whose end face wall is disposed a closed oval-shaped guide in contact with the carriers of the flaps, and a conduit for gas-exchange between the spaces located on both sides of the flaps. The end face surfaces of the flaps and the surfaces of adjacent posts that contact the end face surfaces of the flaps are conjugated, contact one another, each of the flaps separating the compression space from the working space. Suction and exhaust openings are provided. (U.S. Pat. No. 5,261,365, NPC 123-241 published 1993; U.S. Pat. No. 5,345,905, NPC 123-241 published 1994).
A feature of this solution that is advantageous is that both sides of a flap participate in the work cycle of the engine, one side participating as a compression space wall, the other participating as a working space wall.
This technical solution has a number of substantial drawbacks. The carriers are made in the form of cylindrical pins on the end face surfaces of the flaps. This results in that in such an arrangement there will always be gas leakage occurring through slits in the rotor wall and in the body wall. An attempt to reduce these leakages in U.S. Pat. No. 5,261,365, NPC 123-241, published 1993, and U.S. Pat. No. 5,345,905, NPC 123-241, published 1994 by thickening the flap wall results in a decrease of the volumes of the working spaces and the compression spaces.
As a result of the fact that the carrier pins are fixed to flaps (made as an integral part of the flaps) and transmission of the working forces to the engine is effected through these pins, then their design has to be stronger and they necessarily have to be positioned on both sides of the flaps. Otherwise, if the pins are positioned on only one side, they have to be made much bigger, which will result in increased leakage. Furthermore, in the case where the pins are disposed on one side of a flap end face, the flap may be affected by skewness, seizure, and even a failure of the engine may occur. Strengthening the pins and increasing the rigidity of the flaps by increasing their size is also unacceptable here, since this will result in a reduction of the working volumes of the engine.
Another drawback is that in such an engine the carrier is situated in a high-temperature zone, it cannot be cooled well, and acceptable working conditions for the carrier-guide groove friction pair cannot be provided.
A very substantial drawback of the solutions disclosed in U.S. Pat. No. 5,261,365, NPC 123-241, published 1993 and U.S. Pat. No. 5,345,905, NPC 123-241 published 1994, is that the guide for the carriers, which is made in the form of grooves on the end face walls of the body, has a complex shape. This results in that with such a groove:
a) it is virtually impossible to achieve a sufficiently high frequency of engine rotor rotation;
b) it is technologically difficult to attain high-precision manufacture and high quality of the groove surface. The material of which this part should be made, should, on the one hand, be easily machined and be sufficiently ductile in view of being subjected to impact loads, and, on the other hand, should have very high hardness so that it would be capable of working for a lengthy period under conditions of continuous friction of the groove-carrier pair.
The object of the invention is to create a guide of such a shape, that it, while providing good smoothness of travel of a carrier thereon, would be simple to manufacture with high quality of the working surfaces. Achievement of this object makes it possible to obtain high frequencies of engine rotor rotation.
Additional objects of the invention are to create normal working conditions for the carrier-guide pair as regards temperature, lubrication quality, and, furthermore, to obtain a torque on the engine rotor that is also due to the reactive force obtained during waste gas exhaust (by use of a turbo-effect).
This object is attained in that in a rotary-turbine internal combustion engine comprising a rotor having longitudinal flaps that are swivel-mounted on the rotor in the area of the external diameter along its rotation axis and separate one from another the spaces arranged therein on both sides of each flap, the rotor being positioned in a cylindrical body on whose end face wall is arranged a closed guide in contact with carriers of the flaps, and a conduit for gas-exchange between the spaces disposed on both sides of the flaps, a guide therein and disposed on the end face wall of the body being made as an annular guide, and its longitudinal axis is set with an eccentricity relative to the rotation axis of the rotor. This object is also attained in that the annular guide is made in a floating ring that is coaxial with the guide and is positioned on the end face wall of the body.
The invention is novel in that the guide, disposed on the end face wall of the body, is made annular and its longitudinal axis is set with an eccentricity relative to the rotation axis of the rotor, the guide may be made in a floating ring that is coaxial with the guide and is positioned on the end face wall of the body, for example in the form of a groove extending to the end face of the floating ring.
Furthermore, the invention may be provided with the following features:
a) for a rotor having an end face wallxe2x80x94each carrier is made in the form of a crank positioned outside the wall and rigidly connected to a flap, so that the axes of rotation of the crank and the flap swivel coincide, and a second end of the crank contacts the guide;
b) a second end face of the rotor is made to directly contact the second end face wall of the body, which wall is provided with a suction opening that connects to a space under a flap, and further is provided with an inlet and an outlet of the gas-exchange conduit, the inlet of the gas-exchange conduit being disposed opposite the space under the flap in the area of the minimal distance between the flap and the rotation axis of the rotor, and the outlet of the gas-exchange conduit being disposed opposite the space above the flap, the suction opening being disposed in an angular position in the area of maximal displacement of the guide profile with respect to the rotation axis of the rotor; the inlet and outlet of the gas-exchange conduit and also an exhaust opening being disposed in an angular position in the area of the minimal displacement of the guide profile with respect to the rotation axis of the rotor;
c) the engine is made as a unit of two single engines that face one another via the end face walls of the bodies, the walls directly contacting the end faces of the rotors, shafts of the rotors are rigidly interconnected, wherein the walls of the bodies form an integral end face wall of the unit, eccentricities of the longitudinal axes of the guides of the two engines are directed in directions that are opposite to the axis of rotation of the rotors;
d) an additional space that communicates with the existing space is formed on the rotor wall under each of the flaps, a through opening that communicates with the gas-exchange conduit inlet is made in the wall of the additional space;
e) the inlet of the gas-exchange conduit on the end face wall of the body is provided with a segment groove that is directed in the direction opposite to the direction of rotation of the rotor;
f) the rotor along its external diameter is provided with a wall, tangential openings, for example in the form of slot nozzles, being made in the wall;
g) the suction opening is made arched and extends in a direction that is opposite to the direction of rotation of the rotor.
Making the guide annular makes it possible to attain the maximally high frequencies of rotation of the rotor in such an engine, which frequencies are attained owing to smoothness of the rolling motion of the guide profile and owing to the quality of the working surfaces of the guide. High precision in manufacturing, high surface finish, quality of the surface layer in respect to hardness and coatings are easily ensured in this case.
Setting the longitudinal axis of the annular guide with an eccentricity relative to the rotation axis of the rotor provides for cyclic turning the flaps when use is made of a guide which is the simplest as regards the technology utilized. Each flap, using its carrier that rolls on a guide which is positioned with an eccentricity relative to the rotation axis of the rotor, for one complete revolution of the engine will carry out, via its external side, compression of the air over the flap and expansion of the hot gas, and the internal side of the flap will ensure suction of the air, its slight precompression and transfer of this precompressed air to blow the space above the flap and fill this space with air for further compression therein. In one complete revolution of the rotor, the flap makes it possible to carry out the complete cycle of a two-stroke engine. The number of such complete cycles in one revolution of the rotor will be equal to the number of flaps provided on the rotor.
Making the annular guide in a floating ring that is coaxial with the guide and is disposed on the end face wall of the body makes it possible, as a result of the circular rotation of this ring, for ever new regions of the ring to contact the second end of the carrier, which enhances its service life. Rotation of the floating ring relative to the body reduces the relative velocity of the end of the carrier and of the guide. Moreover, the floating ring is an excellent damper. An annular groove that will comprise the guide is easily made in this ring.
Making each carrier in the form of a crank positioned outside the side wall of the rotor, one end of the crank contacting the guiding groove, both the crank itself and the point of contact with the guide will be located in the zone of relatively low temperatures, which makes it possible to organize reliable oil cooling in this location. In such an arrangement the lateral wall of the rotor now reliably covers the high temperature zone.
Rigidly connecting the crank to a flap in such a manner that their rotation axes will coincide, the torque effected from the flap to the crank will now be transmitted via the swivel shaft, which shaft is easily sealed. Strengthening this assembly will not be difficult, since even substantial strengthening of the swivel will cause a minimal reduction of the working volumes of the engine spaces. The possibility to transmit large torques via a system of cranks, disposed on one side of the rotor, will free the second wall of the body and make it possible to use it for other purposes that are very important for the engine.
Making the second end face of the rotor in direct contact with the end face wall of the body, the second end face wall of the body becomes a portion of the spaces above and under each of the flaps, and therefore it is easy to make the suction opening, having the required working area, and also the inlet and outlet of the gas-exchange conduit on that wall.
Arranging the gas-exchange conduit inlet opposite the space under the flap in the area of the minimal distance between it and the rotation axis of the rotor, and its outlet opposite the space above the flap, and turning the suction opening in an angular position in the area of the maximum shift of the guide profile with respect to the rotation axis of the rotor, and arranging the inlet and outlet of the gas-exchange conduit and also the exhaust opening in the area of the minimum shift of the guide profile with respect to the rotation axis of the rotor, it is possible to carry out the selected cycle of operation of the proposed engine, i.e. the two-stroke cycle.
Making the unit as consisting of two engines facing one another by the end face walls of the bodies, which directly contact the end faces of the rotors, and rigidly connecting the rotor shafts to each other, a single end face wall of the unit is obtained. Having such a single end face wall of the unit, which wall is in direct contact with two rotors composing a single whole, and directing the eccentricities of the longitudinal axes of the guides of these engines in directions that are opposite to the axis of rotation of the rotors, a virtually balanced system of two rotors will be provided. In this system the forced imbalance of one rotor, occurring during operation of the engine, is compensated by the oppositely directed forced disbalance of the other rotor, occurring due to movement of the flaps. Furthermore, the necessity of installing two flywheels-counterbalances, as in the Wankel engine, will be obviated.
Providing an additional space on the rotor wall under each of the flaps, which space communicates with the existing space and has a through opening in the wall thereof, the opening communicating with the gas exchange conduit inlet, a space is formed, by means of which the precompression pressure in the space under the flap may be adjusted. This pressure must be selected during operational development of an engine, taking into account that this pressure should be minimal because energy is consumed, but should be sufficient to provide guaranteed blowing of the waste gases from the space above the flap and filling it with clean air.
Providing the gas-exchange conduit inlet on the end face wall of the body with a segment groove directed opposite to the direction of rotation of the rotor makes it possible to adjust the precompression pressure in the space under the flap. This becomes possible in view of the fact that the air for blowing is initially taken from zones having lower air pressure.
Providing the rotor, on its external diameter, with a wall having tangential openings, it becomes possible to also obtain a torque on the rotor by virtue of the reactive force brought about during blowing of the hot gas through these openings, i.e. there is the possibility to use the turbine effect and have an almost complete expansion of the hot gases up to the atmospheric pressure. The turbine effect is enhanced when the tangential openings are made in the form of slot nozzles.
Making the suction opening arched, extended in the direction opposite to the direction of rotation of the rotor, together with increasing the suction area, the suction can begin virtually immediately after the compressed air has been evacuated from the space under the flap for blowing, and this means that there will be no negative pressure (vacuum) under the flap, and no expenditure of energy for this will be required.